From f8b5473fcbddbfde827ecf82aa0e81fa2a878220 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Sat, 1 Jul 2006 22:30:08 +0100 Subject: [PATCH] [ARM] 3690/1: genirq: Introduce and make use of dummy irq chip Patch from Thomas Gleixner From: Thomas Gleixner ARM has a couple of really dumb interrupt controllers. Implement a generic one and fixup the ARM migration. ARM reused the no_irq_chip for this purpose, but this does not work out for platforms which are not converted to the new interrupt type handling model. Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar Signed-off-by: Russell King --- include/linux/irq.h | 3 ++- kernel/irq/chip.c | 15 ++++++++++++--- kernel/irq/handle.c | 16 ++++++++++++++++ 3 files changed, 30 insertions(+), 4 deletions(-) diff --git a/include/linux/irq.h b/include/linux/irq.h index 0832149cdb..00b6ef8b2f 100644 --- a/include/linux/irq.h +++ b/include/linux/irq.h @@ -348,8 +348,9 @@ extern int noirqdebug_setup(char *str); /* Checks whether the interrupt can be requested by request_irq(): */ extern int can_request_irq(unsigned int irq, unsigned long irqflags); -/* Dummy irq-chip implementation: */ +/* Dummy irq-chip implementations: */ extern struct irq_chip no_irq_chip; +extern struct irq_chip dummy_irq_chip; extern void set_irq_chip_and_handler(unsigned int irq, struct irq_chip *chip, diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c index 4a0952d945..54105bdfe2 100644 --- a/kernel/irq/chip.c +++ b/kernel/irq/chip.c @@ -462,9 +462,18 @@ __set_irq_handler(unsigned int irq, if (!handle) handle = handle_bad_irq; - if (is_chained && desc->chip == &no_irq_chip) - printk(KERN_WARNING "Trying to install " - "chained interrupt type for IRQ%d\n", irq); + if (desc->chip == &no_irq_chip) { + printk(KERN_WARNING "Trying to install %sinterrupt handler " + "for IRQ%d\n", is_chained ? "chained " : " ", irq); + /* + * Some ARM implementations install a handler for really dumb + * interrupt hardware without setting an irq_chip. This worked + * with the ARM no_irq_chip but the check in setup_irq would + * prevent us to setup the interrupt at all. Switch it to + * dummy_irq_chip for easy transition. + */ + desc->chip = &dummy_irq_chip; + } spin_lock_irqsave(&desc->lock, flags); diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c index 961b875917..e71266c380 100644 --- a/kernel/irq/handle.c +++ b/kernel/irq/handle.c @@ -95,6 +95,22 @@ struct irq_chip no_irq_chip = { .end = noop, }; +/* + * Generic dummy implementation which can be used for + * real dumb interrupt sources + */ +struct irq_chip dummy_irq_chip = { + .name = "dummy", + .startup = noop_ret, + .shutdown = noop, + .enable = noop, + .disable = noop, + .ack = noop, + .mask = noop, + .unmask = noop, + .end = noop, +}; + /* * Special, empty irq handler: */ -- 2.39.5